On Tuesday Major League Baseball announced that Mariners second baseman Robinson Cano was suspended for use of a banned substance, Furosemide, a diuretic known as a masking agent for performance enhancing drugs. The Mariners will now be without their most indispensable player for 80 games (and also in the postseason, if the Mariners qualify). This does not relate to the Red Sox directly beyond the fact that Boston will now face a Cano-less Mariners team for seven games in June, but it does raise an interesting question: Who are the most irreplaceable players on the Red Sox?

Answering this requires not just a list of who is playing well this season, but understanding what the Red Sox would miss from that player as well as how easily they could replace the lost production. It’s also a subjective list, especially towards the back, where the differences between value and replacement value tend to be much closer.